The field of this invention relates to aromatic polyacyl compounds of polyphenyl structure suitable for polymers useful for forming shaped objects, such as film, fiber and molded parts. The esters are suitable as plasticizers for polyvinylchloride and other polymers.
As is well known, the mechanical and physical properties of a fiber or film depend on the chemical structure of the polymer from which they are made. For example, the melting point, molding temperature, and glass transition temperature of the polymer composition control many of the physical properties and fabrication of the shaped objects. The melting point determines thermal resistance and heat-setting temperature of fibers. Molding temperature determines fabrication temperature. Glass transistion temperature (Tg) determines initial modulus, tensile strain recovery, work of recovery, drape and hand, wash-and-wear characteristics, comfort factors, and resilience of fibers. The main molecular factors that influence these properties include chain stiffness, the intermolecular forces, orientation, and crystallinity.
Accordingly, there has been considerable interest in developing aromatic symmetrical acids as precursors for thermally stable polymers, such as polyesters or polyamides. It is well known that the introduction of aromatic units in the polymer chain backbone results in high bond energies, a low degree of reactivity, and rigidity of the polymer chain structure. The use of aliphatic units in the polymer chain backbone results in flexibility, lower temperature characteristics, and decreased strength as compared with the aromatic types.
Substantially all commercial polyester fibers are based on terephthalic acid. While these fibers have many excellent properties there is a need for polyester fibers having a higher Tg than provided by terephthalic acid polyesters. Recently, 2,6-naphthalene dicarboxylic acid has been proposed as a suitable aromatic acid for producing polyesters suitable for tire cord. This acid provides polyesters having a higher Tg than those based on terephthalic acid. For example, poly(ethylene terephthalate) has a Tg of 74.degree. C. whereas poly(ethylene 2,6-naphthalate) has a Tg of 115.degree.-125.degree. C. However, the difficulties of manufacturing the precursor, i.e., 2,6-dimethylnaphthalene, have made the production of this acid technically difficult and economically costly. The acid can require a four-step synthesis with attendant loss in yield and consequent high cost.
Various other organic polymers have been suggested for use as high temperature fibers, such as copolyamides (Kevlar), polybenzimidazoles, polyoxadiazoles, polyimides and phenylene ring systems (polyphenylenes). Polyarylates and polycarbonates have been suggested for use as engineering plastics. However, all of these are costly and/or difficult to manufacture. Accordingly, there is a need for new aromatic acids suitable for preparing polymers for many uses.
It is the object of this invention to provide a new group of aromatic polycarboxylic acids of polyphenyl structure that will meet this need. Another object of this invention is to provide a process for making these acids. Another object of this invention is to provide a new polycarboxylic acid, specifically 2,3-di-(4-carboxyphenyl) oxirane, for use in polymer chains. A further object is to provide novel polymers, both polyesters and copolyesters, made from these acids. Other and further objects of this invention will be apparent from the following description.
The field of this invention, accordingly, has three aspects. First, it relates to novel compositions of matter that are oxirane polyphenylacyl compounds and to the method of preparing these acyl compounds. Second, it relates to novel polyesters based on oxirane polyphenylacyl compounds. Third, it relates to novel copolyesters based on these same novel acyl compounds.
These novel oxirane polyphenylacyl compounds (acids, acyl halides, simple esters, e.g., methyl, etc.) are desirable intermediates for producing condensation polymers, such as polyesters and copolyesters suitable for shaped articles as film, fiber, and molded parts. The esters of these acids and monohydric alcohols containing 1 to 24 carbon atoms can be used as plasticizers for polyvinylchloride (PVC).
It has been found in accordance with this invention that 2,3-di-(4-carboxyphenyl) oxirane can be prepared by the peracid epoxidation of stilbenedicarboxylic acid and polymers therefrom with diols and other dibasic acids to produce polyesters and copolyesters in which the epoxide moiety is retained. Cross-linking of the polyester or copolyester initiated by strong acids or bases affords a finished polyester or copolyester with improved properties, such as tensile strength, melting point, and solvent resistance. The finished polyesters and copolyesters are suitable for use in coatings, as a polymeric stabilizer and/or as polymers suitable for forming shaped objects such as film, fiber and molded parts.
Accordingly, this invention relates to a new family of compositions of matter having the structural formula ##STR1## wherein A is selected from the group consisting of divalent aliphatic or alkylene moieties and divalent aromatic moieties consisting of an alkylene group, a cycloakylene group and an alkylene-oxyalkylene group containing from two to 24 carbon atoms and an arylene group containing a benzenoid ring radical selected from the group consisting of phenylene, naphthylene, anthrylene, phenanthrylene, benzothienylidene, and fluorenylidene moieties and ring substitution products thereof, and n is an integer from 1 to 8,000. More particularly, it relates to compositions of matter wherein a condensation polymer of a diol HO--A--OH and an epoxide of stilbene dicarboxylic acid or derivative thereof, are reacted with formation of a polyester retaining the epoxy unit, and wherein the diol is an alkanediol and A is ethylene, propylene, trimethylene, 1,3-isobutylene, pentamethylene, neopentylene, 2,2-diethyl-1,3 propylene, hexamethylene, 2,2,4-trimethyl-1,3-pentylene, 2-methyl-2,4-pentylene, decamethylene, 1,4-cyclohexylene, 1,4-cyclohexanedimethylene and ethyleneoxyethylene. The alkanediols can be obtained from a variety of commercially available alkanediols. Examples of such compounds include ethylene glycol, propylene glycol, 1,4-butylene glycol, 2,2-dimethyl 1,3-propanediol, 2-methyl-3-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, 1,4-cyclohexanediol, etc.
This invention also relates to a new family of resins which are essentially linear copolyesters comprising units of a polyhydric alcohol component comprising at least one dihydric alcohol moiety and a dicarboxylic component wherein said dicarboxylic component comprises terephthalate moieties and 2,3-dicarboxyphenyl oxirane moieties in a range of mole ratios of from 19:1 to B 1:19.
Syntheses of epoxides and of trans-stilbene oxide (Organic Syntheses, 4, 860, Wiley, N.Y. (1963)) are well-known in the prior art. trans-Stilbene oxide has been prepared by the reaction of silver oxide with the methiodide of 1,2-diphenyl-2-dimethylaminoethanol, by the reaction of hydrazine with hydrobenzoin, and the reaction of peracetic acid or perbenzoic acid with trans-stilbene. However, to the best of our knowledge, epoxides of stilbenedicarboxylic acid are heretofore unknown. Moreover, although it is known in the prior art that compounds containing the epoxide group such as the oxetane ring and oxirane ring are easily polymerized and undergo further reaction by means of the oxetane ring and oxirane ring, epoxides of stilbenedicarboxylic acid and polymers therefrom which retain the oxirane ring, to the best of our knowledge, are heretofore unknown. And although polymeric derivatives of 3,3-bis (aminomethyl)-oxetane and of epoxysuccinyl chloride are in the prior art (T. W. Campbell and R. N. McDonald, J. Polymer Sci., A-1, 1, 2525 (1963) and syntheses of polyesters by epoxidation of unsaturated polyesters have been taught (J. Poly. Sci., Poly. Chem. Ed., 14, 2969 (1976)) it is clear, to the best of our knowledge, that essentially linear polyesters containing the oxirane ring conjointly with two benzene rings have not been known.
In the prior art, the synthesis of polymers with monomers containing the oxetane ring resulted in polymers which showed a strong tendency to crosslink, either on standing at room temperature or on heating at 100.degree.-120.degree. C. overnight or for 24 hours. (T. W. Campbell, et al., J. Poly. Sci., op. cit. p. 2528). Polymers were difficult to obtain uncrosslinked, presumably because of cleavage of the oxetane ring. Synthesis of polyamides having epoxy groups has been reported (J. Appl. Poly. Sci., 23, 827-835 (1979)) wherein dicarboxylic acid chloride having an epoxy group has been used as a monomer. Low temperature and interfacial polycondensations of dicarboxylic acid chloride having an epoxy group with aromatic diamines have been carried out to obtain polyamides having epoxy groups. However, ring opening reactions of epoxy groups using excess amines gave products having poor thermal stability, that is, their decomposition temperatures were lower than those of the original polymers having epoxy groups.
Accordingly, while it is known in the prior art to prepare polyamide polymers containing the oxetane ring or the oxirane ring, the polyamide polymers prepared heretofore have demonstrated characteristics of instability upon standing or heating and the opening of the oxetane ring or the oxirane ring. The reactivity of oxirane ring toward alcohols, amines, diols and diamines as well as to the influence of heat renders the stability of the instant invented family of compounds unexpected and surprising.
It is also well known that stilbenedicarboxylic acid is a versatile chemical building block. U.S. Pat. No. 2,657,195 teaches the preparation of linear polymers from stilbene dicarboxylic acid. The resulting polymer can have recurring units containing double bonds that can be used to alter the character of the molecule after polymer formation by reaction with compounds capable of adding to a double bond. U.S. Pat. No. 3,496,839 teaches preparation of linear unsaturated polyesters produced from 4,4'-stilbenedicarboxylic acid and commercially available alkanediols wherein a process of irradiation improves the physical properties of the polymer with improved heat stability, solvent resistance and tensile strength. U.S. Pat. No. 2,657,194 teaches a process for forming polymers with improved dye receptivity by reaction of a stilbenedicarboxylic acid by using as catalyst Na and Mg with a polyoxyalkylene glycol. U.S. Pat. No. 2,895,947 teaches preparation of esters by the reaction of epoxy-substituted alcohols such as 2,3-epoxypropanol with p,p'-stilbenedicarboxylic acid using tertiary amines as catalysts. U.S. Pat. No. 2,997,391 teaches the preparation of light-sensitive polyamides containing stilbenes by reacting a stilbene with a diamine, a dibasic acid or ester, or amino acid or ester. Swiss Pat. No. 506,583 (C.A. 75, 141977i) teaches stilbenyloxadiazoles, useful as fluorescent whiteners in poly(ethylene terephthalate), nylon 66, and polypropylene. 4-Benzoxazolyl-4'-oxadiazolylstilbenes are prepared by condensing an oxadiazolylstilbenecarboxylic acid with an orthoaminophenol (C.A., 66, 116,706b). Preparation of bis(2-benzoxazolyl) stilbene derivatives for use as optical brightening agents has been taught (Neth. Appl. 6,413,267; C.A., 64, 6800d). 4,4'-Disubstituted stilbenes are prepared by treating stilbene -4,4'-dicarboxylic acid dichlorides with monocarboxylic acid hydrazides (C.A., 65, 841f).
Accordingly, while it is well known to prepare polymers containing the oxetane ring or the oxirane ring, and stilbene derivatives containing stilbenes, the preparation of a stilbene acyl derivative containing an epoxy group has not been known and, notably, the preparation of a stable polymer containing the epoxide group and the stilbene moiety has not been known.